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A207670 Numbers that match polynomials with coefficients in {0,1,2} that are not irreducible modulo 3; complement of A207670.

%I A207670 #7 Aug 19 2021 10:56:38
%S A207670 1,2,9,11,12,13,15,16,18,19,21,23,24,26,27,28,29,30,31,32,33,36,37,39,
%T A207670 40,42,44,45,47,48,50,51,52,54,55,56,57,60,61,62,63,64,66,68,69,70,72,
%U A207670 74,75,76,78,80,81,82,83,84,85,87,88,90,91,93,95,96,98,99,100
%N A207670 Numbers that match polynomials with coefficients in {0,1,2} that are not irreducible modulo 3; complement of A207670.
%C A207670 See the Comments at A207669.
%e A207670 (See the Example section of A207669.)
%t A207670 t = Table[IntegerDigits[n, 3], {n, 1, 1000}];
%t A207670 b[n_] := Reverse[Table[x^k, {k, 0, n}]]
%t A207670 p[n_, x_] := t[[n]].b[-1 + Length[t[[n]]]]
%t A207670 Table[p[n, x], {n, 1, 15}]
%t A207670 u = {}; Do[n++;
%t A207670 If[IrreduciblePolynomialQ[p[n, x], Modulus -> 3],
%t A207670   AppendTo[u, n]], {n, 1, 400}]
%t A207670 u                           (* A207669 *)
%t A207670 Complement[Range[200], %]   (* A207670 *)
%t A207670 b[n_] := FromDigits[IntegerDigits[u, 3][[n]]]
%t A207670 Table[b[n], {n, 1, 50}]     (* A207671 *)
%Y A207670 Cf. A207669.
%K A207670 nonn
%O A207670 1,2
%A A207670 _Clark Kimberling_, Feb 26 2012